Timing of PD-1 Blockade Is Critical to Effective Combination Immunotherapy with Anti-OX40.

ABSTRACT: Purpose: Antibodies specific for inhibitory checkpoints PD-1 and CTLA-4 have shown impressive results against solid tumors. This has fueled interest in novel immunotherapy combinations to affect patients who remain refractory to checkpoint blockade monotherapy. However, how to optimally combine checkpoint blockade with agents targeting T-cell costimulatory receptors, such as OX40, remains a critical question.Experimental Design: We utilized an anti-PD-1-refractory, orthotopically transplanted MMTV-PyMT mammary cancer model to investigate the antitumor effect of an agonist anti-OX40 antibody combined with anti-PD-1. As PD-1 naturally aids in immune contraction after T-cell activation, we treated mice with concurrent combination treatment versus sequentially administering anti-

SUBMITTER: Messenheimer DJ 

PROVIDER: S-EPMC5641261 | biostudies-literature | 2017 Oct

REPOSITORIES: biostudies-literature